Use deduplication with caution, and only if your datasets are useful for dedup. It uses a lot of memory (or SSD, you can add drives as L2ARC to save some money

Use deduplication with caution, and only if your datasets are useful for dedup. It uses a lot of memory (or SSD, you can add drives as L2ARC to save some money), and it can give you a lot of problems when deleting many files and large datasets. The somewhat recent addition of LZ4 compression is quite nice.